Gravity’s Ghost and Big Dog

Scientific Discovery and Social Analysis in the Twenty-First, by Harry Collins

Roughly 50 kilometers east of Baton Rouge, La., lasers ricochet off mirrors that dangle at the ends of a 4-kilometer-long, L-shaped vacuum tube. A nearly identical facility sits almost 3,000 kilometers away in Washington state. The research stations — part of the Laser Interferometer Gravitational-Wave Observatory, or LIGO — are designed to sense gravitational waves, minuscule ripples in the fabric of space. Unlike the recently detected waves from the Big Bang (SN: 4/5/14, p. 6), the waves LIGO picks up will most likely come from black hole or neutron star collisions.

In 2007, and again in 2010, the mirrors at both sites appeared to tremble in unison. Was this the first direct

This article is only available to Science News subscribers. Already a subscriber? Log in now. Or subscribe today for full access.